Rotary buffing tool



y 1947- E. E. NORDGREN ETAL 2,423,992

RoT'ARY BUFFING TOOL Filed April 5, 1 946 Patented July 15, 1947 OFFICE I ROTARY BUFFING TOOL Elmer E. Nordgren and Roy W. Hagenstad, Minneapolis, Minn.

Application April 3, 1946, Serial No. 659,235

4 Claims.

Our invention relates broadly to rotary W ping tools and more specifically to rotary-bufling tools of the type used in the reconditioning of worn engine cylinders.

An important object of our invention is the provision of a tool in which the worn wiping elements can be readily replaced and renewed in a permanent rotary head.

Another object of our invention is the provision of a rotary head having novel anchoring channels for the wiping elements together with novel cooperating anchors for the replaceable wiping elements.

Another important object of our invention is the provision of resilient reinforcing means for the replaceable wiping elements.

The above and other important objects of our invention, as well as the means for carrying the same into effect, will become apparent from the following detailed specification, appended claims and attached drawings.

Referring to the drawings wherein like characters indicate like parts throughout the several views:

Fig. 1 is a side plan view showing our novel rotary buffer being utilized to roughen the walls of a worn engine cylinder;

Fig. 2 is an enlarged bottom plan view of the structure shown in Fig. 1, some parts being broken away;

Fig. 3 is a vertical axial section taken substantially on the line 3-3 of Fig. 1, some parts being broken away;

Fig. 4 is a perspective view of one of the replaceable wiping elements and anchoring bars;

Fig. 5 is a fragmentary view illustrating a modified arrangement of Wiping element, resilient reinforcing element, and anchoring means; and

Fig. 6 is a side plan view of a wiping element and illustrating a modified form of anchoring clip therefor.

Referring more specifically to the drawings, the numeral I illustrates a rotary shaft or shank having its upper end, as shown in Fig. 1, secured to the chuck 2 of a power drill or the like. The lower end of shank I is reduced at 3 so as to provide a shoulder 4. The extreme lower end of reduced portion 3 of shank I is threaded as indicated by the numeral 5. A head 6 having an axial opening I therethrough, of a size to snugly accommodate the reduced end portion 3 of shank I, is preferably, and as shown, of generally cylindrical form. The cylinder block is identified by the letter A.

As shown, particularly in Figs. 2 and 3, the

cylindrical head 6 is provided with a plurality of circumferentially spaced channels 8 which preferably extend throughout the length thereof in parallel relation with the axis of the head, thereby opening through both ends of the head. The channels 8 include inner base portions 9 having substantially cylindrical walls and substantially restricted portions in the form of slots I0 having parallel and radially disposed walls which communicate with the inner base portions 9 and open through the wall of the cylindrical head.

Referring to Fig. 4, the wiping elements II comprise a plurality of superposed plies of abrasive-coated fabric Ila and III), the abrasive sur faces of which are identified by the numeral H0. The inner ends of abrasive sheets Na and III) are securedby glue or other suitable adhesive into the elongated radially-opening slots I2 in anchoring bars I3, preferably, and as shown, being of cylindrical form. It willbe observed here that the width of wipin elements II substantially correspond to the length of the anchoring bars I3 and that the length of the anchoring bars I3 also corresponds substantially to the length of channels 8.

Referring now specifically to Figs. 2 and 3, it will be observed that anchoring bars I3 are adapted to be inserted from either end of the cylindrical head 6, into the enlarged portions 9 of channels 8 and that the anchoring bars are held against movement radially of the head by the restricted portions I II of channels 8. It will also be observed that the wiping elements I I are sufficiently narrow to permit the same to fit into and project outwardly through the restricted portions III of channels 8.

Another important feature of our invention is the use of a resilient reinforcingmember behind the work-engaging faces No of the wipin elements II. These reinforcing elements may be made from any suitable material but preferably, and as shown in Fig. 4, are in the nature of tongue-like springs I4, preferably anchored both in the slots I2 of anchoring bars I3 and also to the wiping elements by such means as staples I5. Reinforcing elements I4 are preferably both narrower and shorter than the wiping elements behind which they are located and tend to exert yielding pressure against the same, thereby of course, increasing the pressure of the wiping elements against the work.

A pair of disc-like plates I6 are adapted to be fitted over the reduced end 3 of shank I, one thereof to be interposed between the shoulder 4 3 and the adjacent end of the head 6, and the other to be interposed between the opposite end of head 6 and a nut I! which is capable of being tightened to the point where head 6 and plates I6 rotate as a unit with shank I.

With respect to the structure shown in Fig. 4, the abrasive surfaces of the wiping elements II may be initially renewed by merely tearing fi the uppermost lay r IIb so as to make available for wiping action the immediately underlying layer Ila. This, of course, may be done without removing the wiping elements I la and the anchoring bars I3 from the channels 8 of head 6. When the abrasive surface of layer Ila has been worn beyond the point of usefulness, the wiping elements lI may be replaced by removing of nut I1 from the threaded end 5 of shank I, then removing the immediately-underlying endplate I6 so as to expose the open ends of channels 8. The worn wiping elements II together with the anchoring bars I3 are then slidably removed from the end of the head 6 and replaced with new inexpensive wipin elements and anchoring bars. Of course the endplates I6 and nut I! are then put in place, bothto lock the wiping elements I I and anchor bars in place, and to cause the head 6 and plates I6 to rotate as aunit with shank I. v

Referring now to the structure of Fig. 5, we there show a modified form of anchor in the nature of spaced rivets or the like I8 which extend crosswise in the suitably-shaped wide bottom portion of channels I9.

Fig. 5 also illustrates a modified form of arranging the abrasive sheets and 2I of the wiping element II. Here the abrasive sheets 20 and ZI are arranged back to back with the abrasive surfaces thereof being indicated by the numerals 20a and 2Ia, respectively. It will be here noted that the resilient reinforcing member I4 is interposed between the abrasive sheets 20 and H. Of course this arrangement of abrasive sheets and resilient reinforcing member is not limited to the anchoring means shown in Fig. 5 but could be used with equal facility with the structures shown in Figs. 4 or 6. Nor is the anchoring means of Fig. 5 to be limitedto thearrangement of abrasive sheets and resilient reinforcing member shown therein, for obviouslysuch anchoring means could be used with equal facility on the arrangement of abrasive sheets and resilient reinforcing member shown in Figs. 4 and 6. However, it should be noted that withthe arrangement of abrasive sheets illustrated in Fig. 5, it is necessary that the nut IT as well as the immediately underlying endplate I6 be removed from the shank I when it is desired to reverse the position of the wiping elements II to make available the opposite unworn side thereof.

In Fig, 6 we illustrate a modified form of anchoring bar which comprises a tube 22 having a slot 23 into which the wiping element II, together with the wiping element II" and resilient reinforcing member I4" are tightly clamped.

The term wiping element as herein used is not limited to abrasive sheeting alone, but is broad enough to include a plurality of bristles mounted in the anchoring means whereby to provide a brush.

In accordance with the patent statutes, we have described the principles of construction and operation of our pullin tool; and while we hav enhead extending parallel with the axis and opening through one end thereof, said channels including restricted radial portions opening through the cylindrical wall of the head and enlarged base portions, elongated anchoring bars removably disposed in the enlarged portions of the channel and being of greater width than that of the restricted portions of the channels, whereby confining the anchoring bars to movement,

lengthwise of the head for removal or replacement through the open ends of the channels at said one end of the head, Wiper elements secured to said anchoring bars and projecting radially outwardly of said head through the restricted portions of the channels, and a plate removably secured to said head in overlapping relation to the open ends of the channels for retaining the anchoring bars in the channels.

2. In a device of the class described, a rotatable cylindrical head, a plurality of circumferentially spaced channels in said head extendin parallel with the axis and opening through both ends thereof, said channels including restricted parallel walled radial portions, opening through the cylindrical wall of the head and enlarged cylindrical base portions,..elongated cylindrical anchoring bars of the length of said channels and substantially of the samediameter as the enlarged base portions thereof and removably disposed therein whereby the anchoring bars are confined to movement into or out of the channels from the ends of the head, wiper elements of a width equal to the lengths of the anchoring bars secured to the bars and projectin radially outwardly through the restrictedportions of the channels, and plates removably secured to 0D- posite ends of the head in lapping relation to the opposite ends of the channelsand portions of said wiper elements for retaining the anchor ing bars in the channels.

3. The structure according to claim 1 together with a leaf spring secured to the intermediate portion of each of said anchoring bars, the leaf springs projecting radially outward of the head through the restricted portions of the channels behind the wiper elements. I

4. The structure according to claim 1 wherein the anchoring bars comprise cylindrical metal tubes having elongated slots extending through their walls and in which the inner ends of the wiper elements are clamped.

ELMER E. NORDGREN. ROY W. HAGENSTAD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,259,475 Koether Oct. 21, 1941 2,194,577 Vonnegut Mar, 26, 1940 2,316,257 Krastin Apr. 13, 1943 

